taylor



(No Model.) 2 Sheets- Sheet 1.

- J. H. TAYLOR.

DIFFERENTIAL PULLEY BLOCK.

No. 304,284. Patented Aug. 26, 1884.

WITNESSES I Q j ETTORIQZQYS. y

- 2 Sheets-Sheet 2-.

(No Model.)

J. H. TAYLOR.

DIFFERENTIAL PULLEYBLOGK.

Patented Aug. 276, 1884.

' ratchet-wheel, F, which is engaged by a number flatten STATES ATENTEFFEQE;

JOHN H. TAYLOR, OF BATAVIA, NEW YORK, ASSIGNOR OF ONE-HALF TO 7 JOHN B.CHADDOCK, OF SAMEPLAOE.

DIFFERENTIAL PULLEY-BLOCK.

:PECIFICATION forming part of Letters Patent No. 304,284, dated August26, 1884.

Application filed July 12, 1854. (No model.)

35'0 all whom it may concern;

Be it known that I, JOHN H. TAYLOR, aciiizen of the United States, and aresident of Batavia, in the county Genesee and State of New York, haveinvented certain new and useful Improvements in Self-Sustaining Pulleys;and I do hereby declare that the following is a full, clear, and exactdescription of the invention, which will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawings, which form a part of this specification,and in which Figure 1 is a side view of my improved selfsustainingpulley. Fig. 2 is a vertical section of the same. Fig. 3 is a view ofthe smaller of the hoisting-pulleys. Fig.4 is a view of the larger ofthe pulleys. Fig. 5 is aview of the cam-pulley; and Figs. 6, 7, and 8are views of the pulley and block, showing the different ways of usingthe pulley with different leverage.

Similar letters of reference indicate corre-' sponding parts in all thefigures.

My invention has relation to self-sustaining or so-called differentialpulleys 5 and it consists in the improved construction and combinationof parts of such a pulley as hereinafter more fully describedandclaimed.

In the accompanying drawings, theletter A indicates the frame of thepulleys, which frame may be of any desirable shape, and may be suspendedor supported in any suitable manner; and B indicates the pin upon whichthe pulleys are journaled.

O is the smaller hoisting-pulley,which has a circumferential groove, D,adapted to receive the hoisting-chain E, which is endless, and the saidpulley has upon its inner face a central of pawls, G, having their innerends, H, rounded, and fitting and rocking in concavo-cylindricalrecesses I in blocks J, secured upon the face of the largerhoisting-pulley, K, which pulley has a circumferential groove, L, forthe reception of the hoisting-chain, and a flange, M, upon the faceadjoining the smaller pulley, and near the edge of the same, and springsN bear against the outer sides of the pawls and against the inner sideof the flange, forcing the pawls to engage the ratchet-wheel. The pawlspulley, and has a circumferential groove, S,

for the reception of an endless chain, T.

U is the traveling pulley, which has a circumferential groove,V, for thereception of the hoisting-chain, and which is journaled in a frame, WV,having means for suspending the burden to be raised, and the pin X, uponwhich the pulley is journaled, has its ends slotted, as shown at Y,adapted to catch and hold alink of the hoisting-chain.

WVheu the pulley is to be used for hoisting heavy burdens, thatportion'of the chainpassing down from the larger pulley is drawndownward, and the burden witl be raised by the larger pulley drawing thechain faster over it than the smaller pulley is allowing the chain topass downward to the traveling pulley, while, when it is desired toraise a lighter burden with greater speed than what is accomplished bythe differential pulleys, the chain passing over the cam-pulley ispulled so as to cause the cam-grooves in the same to force the pins uponthe pawls outward, releasing them from engagement with theratchet-wheel, and allowing the two hoisting-pulleys to revolveindependently, when either side of the pending or looped portion of thechain may be caught in the slotted end of the pin of the travelingpulley, and the pulleys act as the usual double set of pulleys, theportion of the chain which is not caught by the slotted pin beingpulled, and it will be seen that by pulling that side of the pendingportion of the chain which passes from the smaller pulley, andconsequently catching the portion passing from the larger pulley, theleverage will be less, while by reversing the aforesaid order theleverage will be increased. When the pawls are disengaged, the power mayalso be simply applied to the lower end of the looped portion of thechain,

when both portions of the chain will travel in opposite directions overthe hoisting-pulleys, and the burden be raised comparatively fast, butwith very little saving in power.

The chain passing over the cam-pulley may be used for turning thepulleys while hoisting, the ends of the slots bearing against the pins,and thus causing the said cam-pulley and the larger hoisting-pulley torevolve together.

Having thus described my invention, I claim and desire to secure byLetters Patent of the United States- 1. In a selfsustaining ordifferential pulley, the combination of two hoisting-pulleys or sheavesturning independently upon a pm or bolt, a ratchet-wheel secured to onepulley, pawls secured upon the other pulley and having means forengaging and disengaging them with the ratchet-wheel, atraveling pulley,and an endless hoisting-chain traveling over the hoisting-pulleys andunder the traveling pul-' ley,as and for the purpose shown and setforth.

2. In a self-sustaining or differential pulley, the combination of apulley-frame having a central pin or bolt, a smaller hoisting-pulleyjournaled upon the bolt and having a central ratchet-Wheel, a largerhoisting-pulley journaled upon the bolt or pin, and provided withspring-pawls engaging the ratchet-wheel, a traveling pulley, an endlesschain traveling over the hoisting-pulleysand under the traveling pulley,and means, substantially as described, for disengaging the pawls fromthe ratchet-wheel, as and for the purpose shown and set forth. L

3. The combination, in a differential pulley or self-sustaining pulley,of a frame having a pivotal bolt or pin, a smaller hoisting-pulleyhaving a ratchet-wheel at the center of its inner face, a largerhoisting-pulley having a flange upon its face near the edge, and havingblocks upon its face formed with concavo-cylindrical recesses, springpawls fitting with the inner rounded ends in the said recesses andengaging the ratchet-wheel with their outer ends, and provided upontheir sides with laterally-projecting pins sliding in slots in the bodyof the pulley, a pulley having a circun1- ferential groove and havingeccentric or cam slots for the reception of the pins from the pawls, atraveling pulley having means for suspending the burden to be raised, anendless hoisting-chain passing over the hoisting-pul-- leys and underthe traveling pulley, and an endless chain passing over the cam-pulley,as and for the purpose shown and set forth.

In testimony that I claim the foregoing as my own I have hereuntoaflixed my signature in presence of two witnesses.

JOHN II. TAYLOR.

\Vitnesses:

NM. SEouER, D. E. MOELHINNY.

